The present invention relates electric machines, and more precisely, but not exclusively, to installation procedures of an electric machine to a system comprising means for controlling operation of the electric machine and/or other apparatus connected to the electric machine. The invention relates further to a method of installing an electric machine to a system.
Various kinds of electric machines are known. In the industry, the most common electric machine is an alternating current electric motor, such as an asynchronous induction motor or a synchronous motor, providing rotational or linear movement through the output shaft or similar means thereof. The other group of electric machines is formed by generators or alternators providing electricity as output, i.e. accomplishing an opposite electricity-mechanical power transformation. The skilled person is familiar with the general structure, operation, functionality and use of various electric machines, and thus these are not explained in more detail herein.
Normally, the size of an electrical motor is determined by the torque demands and type of the driven device in the system. The system in which the motor is used usually includes various apparatus and components which have to be properly dimensioned and selected relative to each other to avoid any damages caused by improper and unmatching components of the system. For instance, the apparatus of a fixed-speed motor drive such as switches, fuses, contactors, measurement transformers, etc. in the motor starter are selected so that their electrical performance matches the maximal currents, voltages, etc. of the motor.
The motor starters or components thereof may be replaced during maintenance, repair or installation of new equipment to the system. Of course, the size and performance of the replaced or installed components must again match to the size of the motor and/or the other parts and components of the system. It is also possible that the motor or several motors is/are replaced without replacing the motor starter or other components of the system (even if e.g. the motor size changes a little).
Three types of motor starters and feeders which are located in the switchgear are normally used. The fixed motor starter or feeder has relatively low installation cost but when the switchgear has been disconnected from the supply voltage an adding or removing of motor starters or feeders or their components must be performed. Removable motor starter or feeder units can be removed from the equipment compartment when the switchgear is connected. The removable units have plug-in connections to the incoming supply from the distribution bar system in the switchgear, whereas the outgoing cables are connected permanently directly to the apparatus terminals. The electrical connections of a withdrawable type (cassette type) motor starter or feeder are of the plug-in-type which makes its mounting and dismounting very fast. Removable or withdrawable motor starters or feeders are often replaced by another unit during maintenance. It is possible that the replacing unit does not always have equivalent components and thus the quality of motor control or protection may be reduced.
In the case of variable-speed drives, the size and the parameters of the frequency converter installed in the system must be properly selected based on the motor information to ensure correct control and protection of the motor.
The electric machines, and especially electric motors are often protected by a protective device, such as by an electronic protection relay, against e.g. too high voltage or current rates of the system. Before the electric motor is taken into use, the protective device has to be adjusted to take the specific parameters of the particular electric motor into account, so that a correct xe2x80x9clevel of protectionxe2x80x9d is defined for that particular electric motor to be protected.
The required parameters are announced by a special label or plate fixedly attached on the motor housing, usually in a position from which it can be readily seen. This label is often referred to as rating (or rate) plate. Sometimes the label is also referred to as value label (or plate) or type label (or plate). Several international and national standards, such as IEC 34-1, have set the minimum amount of information to be disclosed by a rating plate. Usually the parameters in the rating plate include at least the following information: voltage (U), current (I), power (W), cos "psgr" value, frequency (f), and r/min rate. A rating plate may also include some additional information considered as useful and/or necessary. The additional information includes data such as the phase of the motor, the manufacturer, those standards the motor fulfils/according to which it has been constructed, weight of the motor, special conditions for use, etc.
When installing an electric motor, a technician accomplishing the assembly adjusts or configures manually the protective device and/or other control means in accordance with the information he can read from the rating plate. This manual set up and configuration is time consuming and sensitive to human errors. Especially in cases where the motor is to be assembled to form a part of a substantially large system, the losses e.g. in production, and thus the costs for the losses, can become high during this manual configuration work. In addition, the manual configuration involves always a risk for human errors (e.g. a misread of the rating plate, using the rating plate of another motor, an incorrect setting or a xe2x80x9cforgottenxe2x80x9d and thus undefined parameter).
In addition to the information shown by the rating plate, the control means of a system to which an electric motor has been installed to form a part thereof, may require some additional information to be fed in during the set up and configuration thereof and before the electric motor can be taken into use. This additional information is required especially in cases were condition evaluating and/or overall management and/or control systems are in use. Also frequency converters that supply variable-speed drives need information not normally shown on the rating plate. This additional information may include instructions and parameters for a lubrication system, information concerning the parameters of the bearings installed in the motor, information concerning the thermal behaviour of the motor, information concerning the protection and/or control devices, information concerning maintenance of the motor, etc.
At present this kind of information required by the system algorithm is fed manually to the system, for example by the technicians assembling and configuring the system or the operators using and controlling the system or service personnel accomplishing maintenance or repair to the system. This manual feeding of data involves the same problems as already mentioned above in connection with the manual feeding of the rating plate information.
In the U.S. Pat. No. 5,672,943 (Vivers), xe2x80x9cElectronic Control Apparatusxe2x80x9d, a separate non-volatile memory for storing the location address of each function unit has been presented. Here, the memory unit is physically associated with each motor such that it is resident in the cabling marshalling area of the motor control centre cubicle. When the control wiring has been fixed, the address information can be transferred from the memory unit of the motor to the control unit, and thereafter it can be used by control unit to retrieve information from a location indicated by said address.
U.S. Pat. No. 5,672,943 disclosure focuses on reading a location address information and getting the data from elsewhere based on this address. U.S. Pat. No. 5,672,943 suggest a memory that suits only for withdrawable cassette-type motor units. It does not suggest any possibility to detect and/or to check that a motor or any other component of the system has been replaced, or that the replaced component can be used in the system. There is no actual suggestion how to set-up the system automatically. In a system according to U.S. Pat. No. 5,672,943 one would have to change also the data memory in the motor control centre cubicle or contents of the memory to identify a different motor. The information has to be entered manually to the non-volatile memory of the prior art disclosure during motor installation.
It is an object of the present invention to overcome the disadvantages of the prior art arrangements and to provide a totally new type of solution for installation of an electric machine to a system and/or set-up and/or configuration of a system including at least one electric machine.
An object of the present invention is to provide a solution by means of which a reliable and automatic manner for installing an electric machine to a system including control means for controlling the operation of the electric machine.
An object of the present invention is to provide a solution by means of which the set-up and/or configuration time of a system into which a new electric machine or another component has been installed is decreased.
An object of the present invention is to provide a solution by means of which a risk for human errors during installation and set-up and/or configuration procedures of an electric machine and/or a system including an electric machine is minimised.
An object of the present invention is to provide a solution by means of which parameters relating to a new electric machine to be installed in a system are automatically identified and the system parameters are subsequently updated correspondingly.
An object of the present invention is to provide a solution by means of which correct rating of an electric motor, control means and protection means and a combination of these equipment can be automatically checked.
An object is to provide a new type interface between the electric machine and the control means for data communications.
A further object is to provide means enabling a new type of read-out and/or configuration of machine related parameters of an electric machine.
Other objects and advantages of the present invention will be brought out in the following part of the specification taken in conjunction with the accompanying drawings.
The objects are achieved by providing a system comprising an electric machine, memory means for storing information concerning the electric machine and fixedly attached in connection with the electric machine, at least one control unit adapted to control the operation of the electric machine, an interface between the memory means and said at least one control unit so that said at least one control unit is enabled to read the information stored in the memory means. In the system the control unit is arranged to process the information read from the memory means such that the information becomes verified with default parameters of the system after read-out thereof. In case the information includes parameters which do not match in a predefined manner with the default parameters, the control unit is arranged to either automatically adjust the system in accordance with the information received from the memory means or to prevent start-up of the electric machine or the entire system.
The inventive method of installing an electric machine to a system, said system comprising control means controlling the operation of the electric machine when the electric machine is installed in the system, comprises steps of storing information relating to the electric machine in a memory means attached in connection with the electric machine, reading at least a part of the information stored to the memory means by the control means via an interface between the memory means and the control means, comparing the read information with default parameters to ensure that the electric machine can be used in the system, and in case the read information includes parameters which do not match in a predefined manner with the default parameters either automatically adjusting the control means and/or the system in accordance with the read information or preventing the electric machine and/or system to be started.
Accoding to a further aspect, a rating plate for an electric machine is provided. The rating plate comprises visually readable motor specific rating information in one side thereof. The rating plate is further provided with electric memory means for storing motor specific rating information and means for interfacing a remote control means to enable a read-out of the information by the remote control means.
Several advantages are obtained by means of the present invention. All important information or data concerning an individual electric machine will be stored in memory means attached directly to the machine, such as to an special data chip, microchip or electronic tag attached to the electric machine or a new type rating plate including integrated memory means. All parameters of the electric machine required by the control and/or monitoring equipment of the system or similar apparatus are automatically configured during the installation and set-up procedures, and correspondingly updated at later stages, if this is required. The set-up, configuration and update procedures can be accomplished in a reliable manner, and the risk for human errors in infeeding the data into the controlling means is minimised, while the installation and set-up and/or configuration time is minimised. In case an electric machine has to be replaced by another one in a system including several components, the down time of the system is minimised due to the minimised set-up and configuration time of the electric machine to be changed. The solution ensures that the electric machine and the auxiliary devices match to each other, and that they are driven and protected with correctly selected parameters, and prevent a start-up in a case there is a risk for damages or hazardous situations. Due to the fact that the system parameters relating to the installed electric machine, such as protection parameters, are optimised and selected properly, and this selection and the infeed of the data can be trusted to be correct, the electric machine can be driven in full and optimized capacity. During maintenance of the machinery the risk for incorrect and/or unmatching components and/or configurations is reduced. In case an incorrectly sized replacement machine is installed to the system, any damages or breakages can be avoided as the system knows that the machine is improper, and cannot be run without a risk for damaging the motor or the system itself. An advantage is also that the present invention can be used with all types of motor starters (e.g. fixed, removable or withdrawable cassette-type unit). In addition, the memory unit attached to the motor may contain parameter values, data and information measured or determined specifically for that motor unit by the motor manufacturer or maintenance technician. This data can also be updated during e.g. annual check-ups. The information, such as electrical rating plate data of the electrical motor or the components in the motor starter, can be utilised directly in the system. The present invention makes it also possible to automatically check the short-circuit co-ordination of the motor control system (for example according to the norm IEC 947).
In the following the present invention and the other objects and advantages thereof will be described by way of examples with reference to the annexed drawings, in which similar reference characters throughout the various figures refer to similar features.